Factory automation networks have traditionally utilized proprietary protocols specially designed to facilitate networking of factory automation components, for example, Human-Machine-Interface (HMI) computers, Engineering Workstations, and serial slave devices, at a manufacturing site. Because of their specialized, proprietary nature the costs of these network have remained high.
Recently, interest in using Ethernet in factory automation has grown due the inclusion of inexpensive Ethernet Network Interface Cards (NICs) on most personal computers and the low costs of commercial-off-the shelf components due to commoditization of Ethernet.
In the past, when proprietary manufacturing networks were used on the manufacturing floor no specific security measures were required because security exists due to obscurity. The only NICs available for these proprietary networks are made by specialized equipment vendors such as Rockwell and Honeywell. It would require a sophisticated user to be able to hack the network to cause harm. Since most attacks are done by non-malicious or unsophisticated attackers, there is no specific security features in place to stop attacks in these proprietary networks.
This type of security does not exist for Ethernet. Ethernet Network Interface Cards (NICs) are everywhere. A non-malicious user may plug a laptop PC into a network with Ethernet based manufacturing devices and may unknowingly spread virus or worms which can cause traffic storms. Manufacturing devices can be overwhelmed by these traffic storms thereby causing down time on the manufacturing floor.
Therefore, security measures for protecting devices on the manufacturing floor connected by Ethernet are required in the industry.